糜子雄性不育突变体的创制和遗传分析

摘要

Heterosis plays an important role in development of new crop varieties with high-yielding, good-quality and biotic/abiotic stresses while male sterile line development is the key step to determine the success of heterosis utilization. A male sterile mutant,M207A was created in proso millet (Panicum miliaceum,2n=4x=36) for the first time using 60Co-γ ray mutagenesis. Fertility identification and genetic analysis were carried out to charac-terize the mutant for its possible use for heterosis utilization in proso millet. First the sterility was investigated using both field survey and indoor pollen microscopy identification. Then Pollinated by normal fertile proso millet cultivars, F1 and F2 populations from the mutant were obtained. Meanwhile primary genetic analysis was also conducted using above populations in different experimental sites,seasons and years. The results showed that the male sterile plant exhibited closed glumes,browning and dry anthers with few normal pollens. The sterility was stable and sterility rate was above 95% on average. The segregation ratio of fer-tile to sterile plants was 35:1 in the fertile selfing F2 pop-ulation indicating that the mutant was a genic male sterility belonging to a pollen-less type controlled by a single re-cessive gene. The creation of the mutant, M207A can play a key role for heterosis utilization in proso millet.%杂种优势是培育高产、优质、高抗作物新品种的主要手段，而雄性不育系的选育直接决定着作物杂种优势育种的成功。利用60Co-γ射线诱变首次创制出糜子（Panicum miliaceum，2n=4x=36）雄性不育突变体M207A，并对其进行了育性鉴定和初步的遗传分析，目的是利用该突变体进行糜子杂交种的选育、在糜子中实现杂种优势的利用。首先采用室内花粉镜检与田间调查相结合的方法对突变体进行了育性鉴定；将突变体与育性正常的糜子品种配组杂交获得的F1和F2群体在不同地点、不同年份、不同季节种植，对不育突变体的遗传模式进行了分析。结果表明：不育株花药褐化，无外露，花药干瘪，不育度在95%以上，不育性状稳定；利用育性正常的品种给稳定的突变体进行授粉，其结实率可达到正常水平；自交F2群体中育性分离比例为35：1，符合单基因座位上同源四倍体基因的理论分离比，说明该突变性状是由隐性单基因控制的可遗传的“无花粉型”细胞核雄性不育。雄性不育突变材料M207A的创制，为糜子杂种优势利用奠定了材料基础。